The objective of this research is the assessment of the impact of several non-drug factors upon treatment outcome. This research utilizes the resources of an extensive data bank assembled during the course of a set of double-blind drug trials conducted with anxious and depressed psychiatric outpatients over the past 11 years. Approximately 500 items of information are available on each of approximately 6000 patients. This research examines the impact of three major classes of non-drug factors upon such indices of treatment outcome as symptom change, the reporting of side effects, and patient attrition. These three classes of non-specific factors are: 1) patterns of presenting symptomatology; 2) the nature of the current treatment situation, e.g., aspects of the doctor-patient relationship; and, 3) selected factors in the patients' internal and external environments includng the presence, severity, and content of precipitating stress, the impact of favorable and unfavorable intercurrent external events, and the effects of caffeine and nicotine intake. This research also continues to study, through the use of multiple regression techniques, the stability with which differential drug response can be predicted and the evaluation of the influence of several personality factors on treatment response.